1. Field of the Invention
The invention relates to touch point detection, and in particular, to a method and apparatus for touch point detection employing image analysis technology.
2. Description of the Related Art
Touch control technology is a technology that provides intuitive and easy human interface for various devices, such as mobile devices, displays and hand writing boards. Users may directly touch a touch pad with his/her finger or a stylus, and coordinates of the touch point would be detected by different methods, such as a capacitance circuit array overlaid on the touch pad. An image sensing technique may also be employed to determine coordinates of the touch point. For example, infrared light emitting diode (LED) arrays may be deposited on one horizontal edge and one vertical edge of a rectangle, while two rows of infrared sensors are deposited on the opposite horizontal edge and vertical edges of the rectangle. Thus, an infrared grid is formed on the touch pad. Any touch point on a particular position of the touch pad would cause at least a pair of a horizontal sensor and a vertical sensor to be obstructed from their corresponding infrared light sources, such that the coordinates of the position can be determined.
For the conventional touch detection techniques, however, the cost of LEDs and sensor arrays is high. Thus, for large panel displays, use of the technology is not feasible. Thus, a more flexible structure is desirable.